Abstract

Authors

KOSUGI Yoshiko, ITOH Masayuki, MATSUBARA Takashi, TAKANASHI Satoru, OSAKA Ken'ichi, MIZOTA Yoko, DANNOURA Masako, SHIMAMURA Tetsuya, MAKITA Naoki

Year

2010

Title

Partitioning of respiratory CO2 fluxes in a managed C3 turfgrass field

Journal

Journal of Agricultural Meteorology

Volume

66(3)

Page

151-161

DOI

10.2480/agrmet.66.3.1

Keywords

Activation energy, Autotrophic respiration, Ecosystem respiration, Heterotrophic respiration, Temperature dependence

URL

http://www.jstage.jst.go.jp/article/agrmet/66/3/66_151/_article

Abstract

To evaluate the respiration and temperature dependence of each component of a managed C3 coolseason turfgrass (Kentucky bluegrass, Poa pratensis) field and to elucidate the characteristics of the carbon budget, respiratory CO2 fluxes from leaves, non-assimilatory organs, and decomposition (soil heterotrophic respiration) were measured using a closed dynamic chamber method. Analysis of temperature dependence using the Arrhenius function was performed for partitioning of the components of ecosystem respiration. The activation energy for respiration was 40,200 J mol-1 for non-assimilatory organs, 41,600 J mol-1 for leaves, and 69,800 J mol-1 for heterotrophic respiration. Total ecosystem respiration at 25°C was 9.0 μmol m-2 s-1 in June 2006 and 8.2 μmol m-2 s-1 in August 2007. Leaf, non-assimilatory organ, and heterotrophic respiration at 25°C was 1.7 (19%), 4.8 (53%), and 2.5 (28%) μmol m-2 s-1, respectively, in June 2006, and 1.8 (22%), 4.1 (50%), and 2.3 (28%) μmol m-2 s-1, respectively, in August 2007. A large proportion of non-assimilatory organ respiration coincided with the non-assimilatory organ biomass. At the study site, soil respiration as the sum of non-assimilatory organ and heterotrophic respiration formed 78-81% of the total ecosystem respiration, and the proportion of autotrophic respiration (non-assimilatory organ respiration) to total soil respiration was 64-66%. The total ecosystem respiration and soil respiration were very large in comparison with the values reported for other ecosystems.

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